Planar covariation of elevation angles in prosthetic gait
Planar covariation of elevation angles in prosthetic gait
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DOI：
10.1016/j.gaitpost.2011.12.017
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发表时间：
2012-04-01
期刊：
影响因子：
2.4
通讯作者：
Cheron, G.
中科院分区：
文献类型：
--
作者：
Leurs, F.;Bengoetxea, A.;Cheron, G.
为了实现有效的行走，经股截肢者必须适应人工下肢和健全下肢的协调。我们使用下肢节段的平面共变方法分析了截肢者的运动学策略。当大腿、小腿和脚的仰角相对于其他仰角绘制时，它们描述了一个规则的环，接近于正常成年人的步态平面。这个平面的方向随着速度的增加而改变，这与机械能量节约有关。我们使用光电装置记录新手和专家经股截肢者的两肢节段仰角，并与对照组进行比较。用主成分分析和傅里叶变换描述了这些角度分布的统计结构。典型的椭圆环在假肢行走中被保留，在新手和专家的双腿经股截肢者。这反映了对大腿仰角的特定控制，考虑到整个步态周期中对其他仰角的了解。相对于控制对象的慢速试验平面，快速试验的最佳拟合平面围绕步态环的长轴旋转，对于专家截肢者的健全肢体来说，这一拟合平面甚至更多。相比之下，假肢的平面旋转非常弱或不存在。我们认为这些结果揭示了一个集中指挥的补偿策略。(C) 2011 Elsevier BM。版权所有。
In order to achieve efficacious walking, transfemoral amputees must adapt coordination within both the artificial and the sound lower limb. We analyzed kinematic strategies in amputees using the planar covariation of lower limb segments approach. When the elevation angles of the thigh, shank and foot are plotted one versus the others, they describe a regular loop which lies close to a plane in normal adults' gait. Orientation of this plane changes with increased speed, in relation to mechanical energetic saving. We used an opto-electronic device to record the elevation angles of both limbs' segments of novice and expert transfemoral amputees and compared them to those of control subjects. The statistical structure underlying the distribution of these angles was described by principal component analysis and Fourier transform. The typical elliptic loop was preserved in prosthetic walking, in both limbs in both novice and expert transfemoral amputees. This reflects a specific control over the thigh elevation angle taking into account knowledge of the other elevation angles throughout the gait cycle. The best-fitting plane of faster trials rotates around the long axis of the gait loop with respect to the plane of slower trials for control subjects, and even more for the sound limb of expert amputees. In contrast, plane rotation is very weak or absent for the prosthetic limb. We suggest that these results reveal a centrally commanded compensation strategy. (C) 2011 Elsevier BM. All rights reserved.